Allocating weighted sales revenue to reporting dates - excel

Question

I'm trying to find a way to distribute revenue to specific dates and weight out the numbers. So that if a day falls between my two reporting days, I want it to allocate it based on the difference between the reporting days. So for example if I have reporting dates
20/11/2017
30/11/2017
10/12/2017
20/12/2017
and sale dates with revenue
Sales dates Volumes
22/11/2017 600,000,000
12/12/2017 -100,000,000
13/12/2017 -141,400,000
20/12/2017 -100,962,000
I want the sale made 22/11/2017to be distributed 8/10 to 20/11/2017and 2/10 to 30/11/2017and so on, so that the 4 sales would distribute to
Reporting dates
20/11/2017 480,000,000
30/11/2017 120,000,000
10/12/2017 -178,980,000
20/12/2017 -163,382,000
I have not successfully found any solution, anyone know if I have missed something or have any good ideas how one good build such a settup?

Answer 1

Ok, this solution uses a lot of helper columns as I haven't had time to condense it all down. I'm sure these formula can be improved and maybe even turned into a single formula.
First step is to find the two dates that your revenue should be distributed between.
With your original data in cells A1:B4 this formula placed in cells C1:C4 will return the higher date:
=DATE(YEAR($A1),MONTH($A1),CEILING(DAY($A1),10))
and this, placed in D1:D4 will return the lower date:
=DATE(YEAR($A1),MONTH($A1),FLOOR(DAY($A1),10))
Edit: After spending a bit more time awake you could replace the above two formula with =CEILING($A1,10)-1 and =FLOOR($A1,10)-1 respectively.
Next we find where the sale date is in relation to the upper and lower dates.
In E1:E4 use:
=(C1-A1)/10
and in F1:F4:
=(A1-D1)/10
Now to return the revenue based on that distribution:
In G1:G4 use:
=E1*$B1
The formula in H1:H4 differs slightly as the 100% figure should only be returned once. The revenue for 20/12/2017 will only appear in column H.
=IF(F1=0,B1,F1*$B1)
I've placed the reporting dates in the range J1:J4; so 20/11/2017 in J1, 30/11/2017 in J2, etc.
The formula in K1:K4 is:
=SUMIF(C$1:C$4,$J1,$H$1:$H$4)
The formula in L1:L4 is:
=SUMIF(D$1:D$4,$J1,$G$1:$G$4)
Finally the formula to return your distribution will sum the previous two formula in cells M1:M4:
=SUM(K1:L1)